Detergent compositions



United States PatentO 3,445,386 DETERGENT COMPOSITIONS Ferdinand P. Otto, Woodbury, N.J., and Andreas Logo thetis, Philadelphia, Pa., assignors to Mobil Oil Corporation, a corporation of New York No Drawing. Filed Jan. 13, 1967, Ser. No. 608,969 Int. Cl. Cm 1/48, 1/36; C101 1110 U8. Cl. 25232.7 11 Claims ABSTRACT OF THE DISCLOSURE Lubricant compositions containing polypropenylsuccinimide amides, imidazolines, and imidazolidines, wherein polypropenyl group is derived from polypropene having a molecular weight of from about 500 to about 3000, possess improved detergency at high temperatures. The lubricant compositions can optionally contain alkaline earth metal salts of sulfonic acids and phosphosulfurized polyolefins and zinc dialkyl dithiophosphates. The succinimide products are also useful as fuel additives.

FIELD OF THE INVENTION Recent interest in the use of detergents for such organic fluids as lubricating oils and fuels have lead to the employment of non-metallic compounds. The advantageous feature of these non-metallic detergents is that they do not leave ashy deposits in an engine as do the metallic detergents. Such detergents include alkyl-substituted organic compounds, some of them polymeric in nature, one particular class containing amide or imide groups. The optimum activity of many of these detergents appears to be at low or moderate temperatures only. However, if a lubricating oil containing these additives is used at a high temperature, the results are not as satisfactory as those obtained with metal detergents, such as calcium sulfonate, sulfurized calcium phenate, or metal salts of phosphosulfurized polyolefins.

DESCRIPTION OF PRIOR ART The non-metallic compounds described in US. Patents Nos. 3,172,892, 3,219,666, 3,272,746 and 3,281,428 are directed broadly to polyalkenylsuccinic-type ashless additives, but the polyalkenyl group preferred and actually claimed is consistently the poly-C derivatives. These derivatives have a utility only in low temperature lubri cation. Desirable properties of these additives at high temperatures have not been described before.

SUMMARY OF INVENTION It has now been discovered that polypropylene degrivatives of succinimide amides, imidazolines, and imidazolidines, wherein the propylene group has a molecular weight ranging from about 500 to about 3000, preferably about 800 to 1400, are capable of performing as a detergent in lubricants for engines in which surface temperatures may reach about 400 F. or higher.

PREFERRED EMBODIMENTS 3,445,386 Patented May 20, 1969 wherein R is alkylene having from 1 to 5 carbon atoms and n is from 0 to 10 with a monocarboxylic acid or an aldehyde or ketone. Suitable polyamines include methylenediamine, ethylenediamine, diethylenetriamine, dipi'opylenetriamine, triethylenetetraamine, tetraethylenepentamine, hexaethyleneheptamine, pentaethylenehexamine, and the like.

As disclosed in US. Patent No. 2,568,876, issued on Sept. 25, 1951, an amine may be reacted with a monocarboxylic acid to yield either the amide or the amine imidazoline, by removing either one or two moles of water, respectively, or mixtures of these, or to yield amine salts. For example, the following reaction may occur with an ethylenepolyaminez wherein m is from 1 to 10 and -R' may be hydrogen or a hydrocarbyl radical having in the range of from 1 to about 29 carbon atoms. Aliphatic, cycloaliphatic and aromatic carboxylic acids are included. Such acids as acetic acid, propionic acid, butyric acid, oleic acid, stearic, 'benzoic acid, and the like may be employed; monocarboxylic acids are preferred. The imidazolidine derivative is produced by reacting the amine with an aldehyde or ketone, containing from 1 to about 30 carbon atoms. Butyraldehyde is a preferred reactant.

The amides, imidazoline or imidazolidine compound may be prepared first and then reacted with the succinic reactant, or the corresponding amine and acid (or aldehyde or ketone) may be mixed with succinic reactant to produce the desired product in 'situ.

The polypropenylsuccinic acid or anhydride reactant may be reacted with nitrogen reactants at ratios ranging from about 0.5 to (n+1) moles of succinic reactant per mole of the nitrogen reactant and n is the number of RNH groups in the alkylenepolyamine. A mole ratio of at least 2:1 is preferred.

It is entirely unexpected to find that the polypropylene derivative is considerably more stable and has more eflective detergency properties than that of the neighboring polymers the polybutenyl or the polyisobutenyl analogs. The polypropylenesuccini-rnide imidazoline and imidazolidine products of this invention have far greater stability at high temperatures than hitherto supposed. These compounds also have such superior high temperature detergent properties that they are able to perform for long periods of time in motor lubricants without permitting the formation of undue deposits of sludge or lacquer. The compounds of this invention find important use in the mineral lubricating oils and in water emulsion systems, such as oil-in-water compositions. Other base media include synthetic ester lubricants, polyglycol ether fluids, polyacetals, silicone fluids, and the like.

These polypropenylsuccinimide compounds may be used in the oil together with numerous additives, preferably overbased alkaline earth metal sulfonates, such as those disclosed in US. Patents Nos. 3,158,572 and 3,133,019 or alkaline earth metal phosphosulfurized polyolefins, such as those disclosed in US. Patent No. 3,213,019. Salts containing metal content of from to about 20% by mol concentration are most desirable. Calcium and barium salts are preferred. A further salt useful as a coadditive is the zinc dialkyl dithiophosphates having from 4 to about 20 carbon atoms in the alkyl radical. Excellent oil blends can be prepared from these additives with the polypropenylsuccinimide products and derivatives.

EXAMPLE 1 To a four-neck flash equipped with a mechanical stirrer, thermometer, condenser and inlet feed tube was added 2475 grams (3 moles) of polypropene having a molecular weight of 825 and 392 grams (4 moles) of maleic anhydride. The mixture was heated at 210 to 220 C. for 8 hours as 171 grams (2.5 moles) of chlorine gas was passed through. At the end of this period the reaction mixture was stripped under 5 mm. Hg vacuum for 2 /2 hours to 170 C. to remove unreacted maleic anhydride. The remaining liquid was filtered in a Buchner funnel using diatomaceous earth filter aid. A dark, viscous oil was obtained having the following analysis:

Analysis.Acid No., 54.3 mg. KOH/g.; chlorine,

EXAMPLE 2 Into a reaction vessel similar to that of Example 1 were added 2000 grams of the product of Example 1 and 205.4 grams of l-triethylenetriamine, 2-methyl-2-imidazoline (prepared by reacting one mole of tctraethylenepentamine and 1.2 moles of acetic anhydride) in 735 grams of a process mineral oil. The reaction mixture was heated slowly to 150 C. under a nitrogen gas blanket. The mixture was stripped for 3 hours under 30 mm. Hg vacuum. The mixture was then cooled to 120 C. before the vacuum was released. The dark brown, clear, viscous oil had the following analysis:

Analysis.-Acid No., 7.0 mg. KOH/g.; nitrogen, 2.2%.

EXAMPLE 3 Using the same equipment as in Example 1, a mixture of 5040 grams (4.5 moles) of polypropene having a molecular weight of 1120 and 588 grams (6 moles) of maleic anhydride was heated at about 210 to 220 C. for 8 hours as 470 grams (6.7 moles) of chlorine gas is passed through. The resulting reaction mixture was treated as in Example 1. The final product had the following analysis:

Analysis.--Acid No., 44.24 mg. KOH/g.; chlorine, 0.65%.

EXAMPLE 4 Using the same equipment as in Example 1, 4000 grams of the polypropenylsuccinic anhydride of Example 3 was mixed with 334.8 grams of 1 thiethylenetriamine, 2 methyl-Z-imidazoline in 1445 grams of the process mineral oil. The reaction mixture was heated and sripped according to the conditions of Example 2. The final product had the following analysis:

Analysis.Acid No., 1.6%.

The compositions of this invention were tested in a lubricating oil blend consisting of a straight-grade solvent refined lubricating oil containing 1% by weight of an overbased calcium sulfonate (11.7% calcium), 2.5% by weight of a barium salt of a phosphosulfurized polypropylene (12% barium), and 0.75% by weight of a commercial zinc dialkyl dithiophosphate. To this blend was added 1.34% by weight of the detergent additive. The base stock is a blend of mineral oil having a 64.1 S.U.V. at 210 F.

The compositions of this invention represented by the product of Example 2 are compared in a high temperature engine test with a polybutenylsuccinimide imidazoline prepared in a manner similar to the above examples from polybutene having a molecular weight of about 800.

EVALUATION OF P RODUCT The evaluation in the l-l-I Caterpillar Engine Test is 12.8 mg. KOH/g.; nitrogen,

Speed, r.p.m 1800: 10

Intake air temp., F. 170:5 Coolant out temp., F. 160:5 Oil pressure', p.s.i 30:1 Top ring groove temp., F 500 650 At the end of the test the engine is dismantled and the selected parts of the engine are inspected. The following results wereobtained:

Piston Lacquer Active ingredient Hours rating demerits Poiybutene derivative igs 2 2 Polypropene derivative (Example 2). igg

Discontinued because of fail rating after 240 hrs.

From these results, it may be seen that the lacquer de merits using the polybutene analog is too high to be of acceptable use. Thus, under the high temperatures encountered in the engine this lubricant would be considered to have a fail rating under MIL-L-2l04B specifications after only 240 hours of operation. On the other hand, the polypropene analog after 48 0 hours had considerably less lacquer demerits and the overall piston rating remained at a high level. The oil composition of this test represents a highly satisfactory formulation.

The polypropenylswccinimide imidazoline reaction products, as described in the above examples, represent; the most eifective and therefore the most preferred products of this invention. The predominant component of the reaction products is a polwpropenylsuccinimide imidazoline which contains an additional polypropenylsuccinyl radical attached to an inner nitrogen atom. As indicated previously, the mole ratio of the polypropenylsuccinic acid or anhydride to nitrogen reactant may range from about 0.5 to (n+1), while the preferred mole ratio is at least 2: 1. The terminal nitrogen atom containing two hydrogen atoms, enters into the imide formation, and a second inner nitrogen atom forms a polypropenylsuccinyl monoamido group. For such preferred products of the 2:1 reaction, the alkylenepolyamine amide, imidazoline or imidazolidine must contain at least one nitrogen atom having two hydrogen atoms and a second nitrogen atom containing one hydrogen atom. The structure for the product of the examples, is believed to have the following structure:

wherein R" is the polypropenyl radical.

The invention is not considered limited in any respect by the aforementioned examples or illustrations except as limited by the following claims.

We claim:

1. An organic composition comprising a major amount of an organic fluid, selected [from the group consisting of a lubricating oil and a normally liquid hydrocarbon fuel, and a minor amount sufiicient to impart detergency thereto of an imide reaction product of:

(1) from 2 to (n+1) moles of a polypropenylsuccinic compound selected from the group consisting of polypropenylsuccinic acid and polypropenylsuccinic acid anhydride, wherein the polypropenyl group is derived from a polypropene having a molecular weight of from about 500 to 3000, and

(2) one mole of an alky-lene polyamine reactant selected from the group consisting of a monoamide, an amine imidazoline, and an amine imidazolidine having the structure NH (RNH- RX wherein R is alkylene having 1 to 5 carbon atoms, n is an integer of from to 9, and X is selected from the group consisting of wherein R is selected from the group consisting of hydrogen and hydrocarbyl having 'from 1 to 29 carbon atoms.

2. The composition of claim 1 wherein R is ethylene.

3. The composition of claim 1 wherein there is also present an alkaline earth metal compound selected from the group consisting of an alkaline earth metal sulfonate and a salt of phosphosulfurized polyolefins, said compound containing from mole percent to 20 mole percent of metal.

4. The composition of claim 1 wherein there is also present a zinc dialkyl dithiophosphate having from 4 to about 20 carbon atoms in the alkyl group.

5. The composition of claim 1 wherein the alkylene polyamine reactant is prepared by reacting an alkylene polyamine and a monocarboxylic acid compound selected from the group consisting of monocarboxylic acid and a monocarboxylic acid anhydride and removing (from the reaction mixture from one to two moles of water of reaction.

6. The composition of claim 5 wherein two moles of the polypropenylsuccinic compound is reacted with one ing an imide with a terminal nitrogen atom of the alkylene polyamine reactant.

7. The composition of claim 6 wherein the alkylene polyamine reactant is the reaction product of an ethylene polyamine and a monocarboxylic acid compound, in which a major component of the reaction product has the structure CH2CH2 NHz(CH OH2NH) CH2CHz-N N wherein R is selected from the group consisting of hydrogen and hydrocarbyl'having from 1 to about 29 carbon atoms and m is an integer sufficient to provide at least one inner nitrogen atom and having a maximum of 10.

8. The composition of claim 7 wherein the alkylene polyamine reactant is prepared by reactant tetraethylene pentamine with acetic anhydride.

9. The composition of claim 8 wherein the alkylene polyamine reactant is l-triethylenetriamine, 2-methyl-2- imidazoline.

10. The composition of claim 9 wherein one component of the reaction product has the structure l a C H-C Hz-C 0 0 H:

wherein R" is a propenyl radical having a molecular weight of from 500 to about 3000.

11. The com-position of claim 1 wherein the polypropene has a molecular weight of from about 800 to about 1400.

References Cited UNITED STATES PATENTS 2,568,876 9/1951 White et a1. 3,185,704 5/1965 Kahn et a1. 3,216,936 11/ 196-5 Le Suer.

3,220,949 11/ 1965 Bell et al. 3,272,743 9/1966 Norman et a1. 3,272,746 9/1966 Le Suer et a1. 3,280,034 1 0/ 1966 Anzenberger et al.

PATRICK P. GARVIN, Primary Examiner.

US. Cl. X.R. 44-63, 71; 252-334, 51.5; 2'60309.6, 309.7, 326.3

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,445,386 May 20, 1969 Ferdinand P. Otto et a1.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 51, "l-thiethylenetriamine" should read l-triethylenetriamine Column 4 formula, that portion reading F 2 f 2 i 2 2 --N N should read --I /N \C/ C CH CH Column 6, line 20, "reactant", second occurrence, should read reacting lines 28 to 36, the right-hand portion of the formula should appear as shown below:

CH CH N C H NH C H I l 2 I 2 4' 2 4' r i TH-CH -COOH CH R Signed and sealed this 24th day of March 1970.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR.

Attesting Officer Commissioner of Patents 

